Share Javascript

Javascript functions to share on Facebook, MySpace and Twitter. More sites to be added soon.
function myspaceShare() {
    var i, description, tags, targetUrl;
    tags = document.getElementsByTagName('meta');
    if (tags) {
        for (i = 0; i < tags.length; i = i + 1) {
            if (tags[i].getAttribute('name') === 'description') {
                description = tags[i].getAttribute('content');
            }
        }
    } else {
        description = document.title;
    }
    targetUrl = 'http://www.myspace.com/index.cfm?fuseaction=postto&' +
        't=' + encodeURIComponent(document.title) +
        '&c=' + encodeURIComponent(description.substring(0, 340)) +
        '&u=' + encodeURIComponent(document.location.href) +
        '&r=' + encodeURIComponent(document.location.href);
    window.open(targetUrl);
}
function twitterShare() {
    window.open('http://twitter.com?status=' + encodeURIComponent(document.title + ' - ' + document.location));
}
function facebookShare() {
    var d = document,
        f = 'http://www.facebook.com/share',
        p = '.php?src=bm&v=4&i=1259575049&u=' +
            encodeURIComponent(document.location.href) +
            '&t=' + encodeURIComponent(d.title);
    function a() {
        if (!window.open(f + 'r' + p, 'sharer', 'toolbar=0,status=0,resizable=1,width=626,height=436')) {
            document.location.href = f + p;
        }
    }
    if (/Firefox/.test(navigator.userAgent)) {
        setTimeout(a, 0);
    } else {
        a();
    }
}